Key Idea : ΔH=ΔE+ΔnRT Δn= number of moles of product - number of moles of reactants ΔG=ΔH−TΔS For a spontaneous process ΔG must be negative. PCl5( g)⇌PCl3( g)+Cl2( g) In this reaction Δn=2−1=1 Thus, ΔH is positive, ie,>0 If ΔH is positive, then to maintain the value of ΔG negative, ΔS should be positive, ie,ΔS>0.
For the gas phase reaction, PCl_5(g) ⇌ PCl_3(g)+ Cl_2(g) which of the following conditions are correct?
NEET UG 2008 — Chemistry Organic Chemistry
2008mcqeasy
For the gas phase reaction, PCl5(g)⇌PCl3(g)+Cl2(g) which of the following conditions are correct?
Official previous-year question
Held on 30 Apr 2008 · Verified 9 Jul 2026.
Options
- A
ΔH=0 and ΔS<0
- B
ΔH>0 and ΔS>0
- C
ΔH<0 and ΔS<0
- D
ΔH>0 and ΔS<0
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